**AD9708AR: A Comprehensive Technical Overview of the 8-Bit, 100 MSPS Digital-to-Analog Converter**
The **AD9708AR** from Analog Devices represents a pivotal component in the realm of digital-to-analog conversion, engineered to deliver high-speed performance with precision. As an **8-bit resolution**, **100 MSPS (Mega Samples Per Second)** DAC, it is designed for applications demanding rapid signal generation and high-frequency operation, such as communications systems, video processing, and high-speed instrumentation.
At the core of the AD9708AR is a segmented, current-steering architecture that ensures excellent dynamic performance and low glitch energy. This design minimizes transient voltages during code transitions, which is critical for maintaining signal integrity in high-speed systems. The converter utilizes a **complimentary bipolar-CMOS process**, enabling it to achieve a remarkable balance between speed, power consumption, and integration.
The device operates from a single **+5V power supply**, typically consuming just 60 mW of power at 100 MSPS, making it suitable for power-sensitive designs. Its output is provided as a differential current, which can be easily converted to a voltage using an external operational amplifier and resistor network. This configuration offers flexibility in setting the full-scale output current, typically adjustable between 2 mA and 20 mA via a single resistor.
A key feature of the AD9708AR is its **on-chip reference circuit**, which includes a temperature-compensated bandgap reference and control amplifier. This integrated reference enhances design simplicity and stability over temperature variations. For applications requiring improved accuracy or different reference settings, the device also supports an external reference input.
The digital interface is designed for ease of use, accepting straight binary coding for the 8-bit input word. It features a single-port, latched input with **TTL/CMOS compatible** levels, ensuring straightforward interfacing with common DSPs, FPGAs, and microprocessors. The high-speed data input is critical for maintaining the DAC's performance at the maximum sampling rate, and careful attention to digital signal integrity is necessary to avoid degradation.
In terms of performance, the AD9708AR excels with its **excellent spurious-free dynamic range (SFDR)** and low harmonic distortion, which are essential for communication applications where spectral purity is paramount. At a 10 MHz output frequency and 100 MSPS update rate, the SFDR typically remains above 50 dBc, demonstrating its capability to generate clean analog signals from digital data.
Packaged in a 28-lead SOIC (Small Outline Integrated Circuit), the AD9708AR offers a compact footprint for space-constrained applications while providing robust thermal and electrical performance.
**ICGOO FIND**
The AD9708AR stands as a robust and efficient solution for high-speed digital-to-analog conversion, integrating critical features like an on-chip reference and low-power operation into a single IC. Its architecture ensures high performance in demanding applications, making it a reliable choice for designers seeking a balance of speed, resolution, and power efficiency.
**Keywords:**
Digital-to-Analog Converter (DAC)
8-Bit Resolution
100 MSPS
Spurious-Free Dynamic Range (SFDR)
Current-Steering Architecture
